Pipelines are used to transport fluids in various industries, including chemical, oil and gas, and manufacturing. These industries use processes that require fluid flow rates to be accurately measured. These measurements are performed at locations known as meter stations using a variety of different meter types. These meters function in different ways, they can use, for example, differential pressure of the fluid across an obstruction, ultrasonic signal travel times, turbine blade rotational speed, Coriolis forces, or even electrical and magnetic fields being generated due to bulk fluid movement. Almost all of these measurement methods require use of the fluid velocity distribution, known as a velocity flow profile.
To achieve the most accurate measurements, the flow profile of the fluid entering a metering device should be stable, non-rotating, and symmetric. This type of velocity distribution is known as a fully developed flow profile, and it forms naturally in very long lengths of uninterrupted straight pipe. However, having long lengths of straight pipe is impractical and cost prohibitive. As a result, meter station piping often contains elbows, tees, valves and other assemblies that distort the flow profile into an asymmetric, unstable, and distorted configuration. This makes it very difficult to measure the fluid flow rate in a consistently accurate and repeatable manner.